The Pentagon’s New Laser-Based Tool Uses Your Heartbeat to Track You

The government’s hefty arsenal of surveillance tools just welcomed a powerful new member. Rather than monitoring an external device—a bug or a smartphone—or even the exterior features of your face, the new tech aims straight for your heart. Literally.

First reported by MIT Technology Review, the US Pentagon is developing an infrared laser that captures a person’s unique “cardiac signature” from as far as 200 meters—the length of just over two football fields—away, as long as you’re still. According to Steward Remaly of the Pentagon’s Combating Terrorism Technical Support Office (CTTSO), even longer ranges may be possible with higher intensity lasers.

Although chilling, the tech builds on previous ideas.

Contact infrared sensors have long been used to monitor a person’s pulse, in a clinical setting or when traversing high altitudes. Here, the devices shoot infrared light into a finger and measure how much blood flow alters the refraction. Unlike this classic setup, the Pentagon’s new tech—dubbed Jetson—uses laser doppler vibrometry that detects minute movements on the skin caused by heartbeat.

Currently under development by Ideal Innovations, Inc., a veteran-owned biometrics, forensics, and scientific company based in Arlington, Virginia, the goal of Jetson is to positively identify an individual within five seconds using a “heartprint.”

“Existing long-range biometric methods that rely on facial recognition suffer from acquiring enough pixels at a distance to use the face matching algorithms and require high performance optics to acquire visual signatures at significant distances,” explained the CTTSO. “The Jetson effort…is a ruggedized biometric system that will capture cardiac signatures to aid in the positive identification of an individual” from a distance with little lag time.

Jetson is just the latest attempt at surveillance from a distance. Rather than old-school technologies such as fingerprinting or retinal scans, this new generation of surveillance technologies uses biometrics to monitor your every move—be it face, speech, heartbeat, or even brain activity—from a distance.

The tech may sound extreme, but Jetson is using the same playbook as biometrics for security. And to project where surveillance is going, it pays to look at biometrics research as the canary in the coal mine. Using your finger or face to unlock your phone is just the convenient side of things—what makes your biometric signature secure as a passcode is also what makes you identifiable as an individual.

Face Off

Facial recognition technology is no doubt the current crown prince of surveillance technologies. China readily adopted the tech as part of their Social Credit System, which monitors a civilian’s every move in public to generate a numerical score for compliance. Even here in the US facial recognition is welcomed by law enforcement. Amazon’s Rekognition system, for example, is reportedly “supercharging” police efforts in Oregon and other police departments, despite pressure from civil liberties groups, lawmakers, and even its own shareholders.

Surveillance loves facial recognition because the tech is relatively mature and can be done from a distance. And no doubt, there is value for the technology in long-range counterterrorism. For example, the technology can be used to remotely confirm the identity of a suspect—say, an ISIS leader—and in turn allow a state to authorize an attack.

The problem? Facial recognition software is far from perfect. A study by the ACLU using Rekognition found that the system incorrectly matched 28 members of Congress to mug shots, with the majority being African-American. Technological hiccups aside, a face is relatively easy to disguise. The perfect surveillance system needs to be efficient, effective, and low-error. In other words, it needs something more concrete, immutable, and physiological to target.

That’s where cardiac signatures come in.

Beat of the Heart

To Dr. Wenyao Xu at the State University of New York, the heart is a much better surveillance target than facial recognition. “Compared with face, cardiac biometrics are more stable and can reach more than 98 percent accuracy,” he said.

Back in 2017, his team developed a non-contact, remote biometrics device that uses dimensions of the heart as a person’s identifier for security. His system distills the geometry of a person’s heart—measured by refracting sound waves with Doppler radars—to identify the particular shape and size that characterizes an individual. But because it relies on sound waves, the system could only function up to 30 meters away—a fraction of the Pentagon’s ideal distance.

Other cardiac signatures have also been used for security. The Toronto company Nymi, for example, developed a wearable wristband that uses an employee’s electrocardiogram (ECG), which is also uniquely tailored to each individual, as an access passcode for an enterprise’s secure database.

Jetson extends this approach by co-opting an off-the-shelf device that normally measures vibrations from structures at a distance. The device further utilizes a gimbal to hold its laser beam steady, allowing it to keep its measurements on target. According to MIT Technology Review, the current system takes roughly 30 seconds to generate a good return signal, and it’s only effective if the target is staying put—either standing or sitting.

Despite these caveats, Remaly said that Jetson works with an admirable 95 percent accuracy if the conditions are optimal. In practice, though, this means Jetson isn’t accurate enough to be reliable on its own. If adopted into surveillance tech, it would likely work alongside other measures, such as facial recognition or gait analysis, as secondary confirmation.

In addition, unlike faces and fingerprints, cardiac signatures aren’t exactly standard collection data. For the technology to truly impact surveillance, the government needs to build a new database from scratch. However, the team argues, when deployed over a period of time—sufficient to capture the heartprint of an individual seen doing something they shouldn’t, for example—it may still be used to positively identify a person, even if his or her actual identity remains mysterious. What’s more, clothing isn’t a deterrent since the tech blasts right through.

Military use aside, the Pentagon foresees the technology trickling down into the cultural mainstream. A doctor could remotely monitor his patient’s cardiac rhythms, for example, without having to rely on electrical wires. Nevertheless, like technologies using echolocation to track an elderly person’s gait for falls, it’s an open question if the benefits warrant the invasion of privacy.

Biometrics Revolution

Monitoring the heart may be just the first step in a new age of long-distance biometrics surveillance.

Speech is another identifier under attack. According to the CTTSO, the already-completed project Beetlejuice uses a beam-forming microphone array to monitor an individual’s speech, in addition to performing speaker tagging, tracking, and locating. The tech relies on deep neural networks to reduce noise and allow near real-time situational awareness of incoming signals, filtering speaker, messages, languages, and location, the report stated.

“The capabilities will be integrated into a lightweight platform in support of operators on the move and handle a variety of noisy audio media…This unique combination will improve performance in both noise reduction, source location, and human language technologies,” the team explained.

Going even further, Xu and others are working on “brainprints” for security measures. Unlike facial or cardiac fingerprints, the brain offers an “inexhaustible” source of secure passwords based on its response to various stimuli, explained Xu.

Using EEG, which picks up neural electrical activity from electrodes placed on the scalp, the team can extract automatic and unconscious activation patterns as a “brain password” unique to a particular individual. Of course, so far there isn’t a way to remotely monitor someone’s brain activity or construct a database of initial readings. And unlike a face or retina, a brainprint changes when an individual is faced with another stimulus.

Nevertheless, a snapshot of brain activity perhaps most uniquely represents you, as an individual, and technological challenges haven’t exactly been a deterrent to agencies that stand most to gain (hydrogen bombs, anyone?).

If history’s any indication, security measures based on biometrics are ripe for hacking and tracking. Now, thanks to Jetson, smearing paint on your face or wearing thick jackets will no longer circumvent surveillance monitoring. San Francisco and Somerville, Massachusetts both recently blanket-banned facial recognition software in protection of civil rights, with New York likely to follow in narrower domains. It’s worth keeping an eye on what comes next.

Shelly Xuelai Fan is a neuroscientist-turned-science writer. She completed her PhD in neuroscience at the University of British Columbia, where she developed novel treatments for neurodegeneration. While studying biological brains, she became fascinated with AI and all things biotech. Following graduation, she moved to UCSF to study blood-based factors that rejuvenate aged brains. She is the ...